One of the most sought out quantities in aerodynamic performance measurements of human powered vehicles (e.g., a bicycle) is the drag force acting on the vehicle. Under controlled conditions of high quality low speed wind tunnel facilities, it is possible to perform such measurements in order to find the most suitable vehicle and body position for minimal aerodynamic drag. Aerodynamic analysis of other objects, such as but not limited to ground-based and airborne vehicles, can be similarly performed.
U.S. Pat. No. 8,612,165 discloses a method and system for measuring aerodynamic properties of objects, including determining the dependence of a drag area of an object upon airflow yaw angle and direction. However, this approach requires data to be collected over an entire vehicle trip and analyzed by the computation of multiple virtual elevation profiles to determine a “best fitting” relationship between aerodynamic drag area and airflow yaw angle.
International Patent Application Publication No. WO 2007/038278 discloses an apparatus for measuring static and dynamic pressure and speed and acceleration of a vehicle, in order to calculate power expended to move the vehicle. However, the relationship between wind yaw angle and aerodynamic drag is not fully considered. In addition, the disclosed approach does not adequately accommodate aggressive cross-wind scenarios, or conditions where the vehicle is undergoing significant accelerations or decelerations.
U.S. Pat. No. 9,188,496 discloses a system and method of calculating under changing conditions in real-time aerodynamic drag acting on a rider on a vehicle. However, this methodology and application relies on real-time analysis of one or more force sensors at points of contact between the rider and the vehicle and does not attempt to provide a measurement of wind speed and wind yaw angle.
Therefore there is a need for a method and apparatus for monitoring and/or determining fluid-dynamic (e.g. aerodynamic) drag on an object, using sensors, that is not subject to one or more limitations of the prior art.
This background information is provided to reveal information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present invention.